From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6B1219006B for ; Thu, 30 Oct 2025 11:07:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761822481; cv=none; b=hyzKxkOnpF2l1HBHEUkqruACdthzkGKLHFeYAZm0Iskh8VXMloiA7V89SLtfaLUnh/kE0xaFzCZwipUNggfRf83z5E6DyQtIOMWYGvRX5wOJY4VazQ2vw9MMrpqReYdaxogVwmd5TIRGsa+FUy/aDGnXduPy9y7YlKwe7b+cSQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761822481; c=relaxed/simple; bh=IRKNYtf1vJEwsLDdTQLi5CxovY/yweeQLsKQmUuTsBs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=p8BkZNtktI4RgTKCNx+SITmgli9y9DWhvtAGu+cQBHcCZdytsfIzEnvt/4vNpOgrJHt+HdCu9T9w4K+FsP9gKpy+ifM3U/hYu7z//aLWZpqZ6COsx53lzhEkIxE6Qgv+blWplz3V+DwIaG+wJciMK9BTNIRORHZQU+fmfAqqqA4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=SqK81fQL; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=B38ZA2qA; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="SqK81fQL"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="B38ZA2qA" Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 59U9WJTe3117016 for ; Thu, 30 Oct 2025 11:07:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= K4396cP+NWBPFdj0+tdDVZrkdA3f1TxyUKHP58p9tTU=; b=SqK81fQL7OnZIxji pEfmpGJXtZEIftOjOc5OjMlDiHzngwx0kA4Fy8DSvrawR8+/yWvmq3M3Rn8kGYrK ZWI3RXoxNGAuTIFV1l3IGrR03PLLubH+WnuHFDtg//VvbNpj+vOP/XYGSrvLFEoJ BljeapyzCa36atlWFqIUdVzrKR0fZNX8rzOW9n4GULo3jsJSYjtok+VtsPvRQuMD hzfqgWg4h3d05sPTRwJd8QtKU0uDNmn1sd3cbACPUNrROQPkVNMqP6MqcaMymH9p 7ULqt+EQmLKRpEWcVl4Cm0tpfyWnbv42WDfMEmpIkTWq3x3SZ7oPOJcuEfN+AKe1 hiiOeQ== Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4a45frg8xx-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Thu, 30 Oct 2025 11:07:58 +0000 (GMT) Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-32ec69d22b2so958990a91.1 for ; Thu, 30 Oct 2025 04:07:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1761822478; x=1762427278; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=K4396cP+NWBPFdj0+tdDVZrkdA3f1TxyUKHP58p9tTU=; b=B38ZA2qAjNcQZkCPBAOfAw+wzVkZDsgMzm9OjsI7DFA7oiIWh+Dk40B4tDzaGndtW3 B87m5fu4jtsklJ4hw2KV2AxzyvwaiiH4tu3q+Un+fJ2Coq4GVsxb8cbW+ZszXW2ojrmw 81BjQGnxPOcjkGMGt1vXalC2LWUfSYmBLBsJYSqBcOgFtYKhxsTwCokOmFwOcaLWt4nS ieVhOBDrxfMDlof/8H6ernshooF9+DrxmHHZdCSAgObD4gsb2+JI+BYZT9dASJAT4w1w 4CcIeyz07KA7dyNSZf1TQI6qReog4spM8TZkx3U7LAasUYgvKCVUOCCBnhmMJFLlvHhg LxqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761822478; x=1762427278; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=K4396cP+NWBPFdj0+tdDVZrkdA3f1TxyUKHP58p9tTU=; b=JstBWh0vGA/X25xn/27YnYS1zB+biu1BENqXZk6zwkadmkadzVtCG3mi6blKyCUbCy zPzWnrfaffeFGkDv+iHJGw3z6EfTFDzZRa7ARCNpNt7GYPIAi8sF5rxiotZRSFS1vMw6 UVu48p9evPgHkIa+uNF37JhXvCmQU7w1/GAn1VtsG3w1dUg+i+cPdP5B1Df4oNYwXJmn jfw9E/6Bx6f/HftL6QcoLooxjkp7P7o7WaJXDa4V1W8wqRswLtl6+A/UqJizI/bj1Qqh YyMn5lOF5EiR5JSm/ONF1HisquEIKwYVxxZrmLynPPvweK9jxO9lT+A1PGw+WGF5HSjZ Hcvg== X-Forwarded-Encrypted: i=1; AJvYcCUvvm305N4dcDCD4Atlx8paeAmMLPvgSjhi3VawerAR2T1QSCqxqCyv1oqXRN5yPsO9ON+Y7dOQS7Mx@vger.kernel.org X-Gm-Message-State: AOJu0Yzw1b4eskYG2twBVWMjM0bXvFK4eDUbOip1cNcPwenk/HQ4q1Rg dNSHmq3AB0PqaONJlnlVXyXkDu7d/EGqRMwEKTkbXtihIs9QKKQqdG9cOnk7dheB1fSsKy5un6Q 9J9ZK3MeV+kwGqEAW8jVEgBqSifIbyIHadTmo9afq4HKOnC3b99GXXQiyJaFetjCx X-Gm-Gg: ASbGnctGsaCLph26CbWSfmSgNDXroOjJNPW0NkAMvkXhKOA9FpidEjo/RZ5rhHYz/lN KdihDZqSTEkKuYVRGtnLLxe4PaCF6uvC1ZOdbR90Ymdm8W5K/zGEiQHsdW9qoBCmj7BI4YQxx9O soafL2kvb8rdrRdqtfw67tydmFN41JucBRZVVVEd1KuYsRNH2tI9DmclmgR2lDhCjfMdjcbmDAK jXc4QEomYigf8ZI8349PuO1vZj/8JhlMXHZBShjUjlR9PJB/b+RGo7bbwnPwxX3LTXXoiPsowfC 36BYaE2Vh9N1nazFIhUmiKJVlH5Kq8zcQxhQXDbQ0kP5OOKLe5cCuLE6EiI83rpqQauM55kt8Yf ZzGB3Z4V4Fc3VorABlVaohlYPB0mHIo3MXYpNOJGMM9qunVhXVVY+UYZ/pXv14NDMl7Wnhw== X-Received: by 2002:a17:90b:3ccb:b0:340:299d:f746 with SMTP id 98e67ed59e1d1-3404c3d7690mr3680408a91.8.1761822477517; Thu, 30 Oct 2025 04:07:57 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGnPeaFBA+lcam7IsugHvorTigV+88PHITZ9ftmVx6VcbOITX10+z6BNS3781eZvJw0PKFtPA== X-Received: by 2002:a17:90b:3ccb:b0:340:299d:f746 with SMTP id 98e67ed59e1d1-3404c3d7690mr3680356a91.8.1761822476895; Thu, 30 Oct 2025 04:07:56 -0700 (PDT) Received: from [10.133.33.50] (tpe-colo-wan-fw-bordernet.qualcomm.com. [103.229.16.4]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-340509e95a3sm2234442a91.19.2025.10.30.04.07.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Oct 2025 04:07:56 -0700 (PDT) Message-ID: Date: Thu, 30 Oct 2025 19:07:50 +0800 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: dts: qcom: Add backlight support for eDP panel To: Konrad Dybcio , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20251028-hamoa_dvt_backlight-v1-1-97ecb8d0ad01@oss.qualcomm.com> <0cf2521b-8d05-42f0-aab8-35cd370e599e@oss.qualcomm.com> <8caa1cec-d881-4e77-8d77-be043f8d13d6@oss.qualcomm.com> Content-Language: en-US From: Yongxing Mou In-Reply-To: <8caa1cec-d881-4e77-8d77-be043f8d13d6@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Authority-Analysis: v=2.4 cv=KupAGGWN c=1 sm=1 tr=0 ts=6903470e cx=c_pps a=RP+M6JBNLl+fLTcSJhASfg==:117 a=nuhDOHQX5FNHPW3J6Bj6AA==:17 a=IkcTkHD0fZMA:10 a=x6icFKpwvdMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=KKAkSRfTAAAA:8 a=EUspDBNiAAAA:8 a=gZJ2WMP_fuF1vj9OyeAA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=iS9zxrgQBfv6-_F4QbHw:22 a=cvBusfyB2V15izCimMoJ:22 X-Proofpoint-ORIG-GUID: OsXKUsJ0myFiAWjhLzBvE98HLvBz9S-y X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMDMwMDA5MCBTYWx0ZWRfX22PrVF1zJRhD JwQnTXdfPcQzeqt/b4O6LM7VmTUoOkdZ2amlNs6rfjC+hd82NLVJtjSQSV/oeHEZb9RhjQSaRs5 6Ze7/Y0DAyYWgE8xXlTbIpMKOKMnFbVf5DmS3ZIRWPaV1hW9VTnQro6T2zGQUlvLyVYA4Jz8xET IOmVL3Qt1BzjR/HdPKRPOjs3U45zWV+9kuWKpxWWMM4xcBJTskmV76bYISzajy8X+gXk/dacLAZ Bd+japN2eRPk/hkFAeLZqcAxj8XP23HNUCG1Pvb4vwdOgm7SKGoVrSQamXxnd8ebE264ZZ6fDf8 WMcoLM6T62QTXwX1u4fb8f2MjWXBIJamL5wrB1XZ38KJpzrF5HMdpTiGxH08X1WIaNBIxejvj/5 gJjRvQCB0NZ2plPOrpSsBBXia0UixA== X-Proofpoint-GUID: OsXKUsJ0myFiAWjhLzBvE98HLvBz9S-y X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-10-30_03,2025-10-29_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 priorityscore=1501 clxscore=1015 spamscore=0 impostorscore=0 adultscore=0 phishscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2510240001 definitions=main-2510300090 On 10/30/2025 5:41 PM, Konrad Dybcio wrote: > On 10/30/25 10:08 AM, Yongxing Mou wrote: >> >> >> On 10/28/2025 5:08 PM, Konrad Dybcio wrote: >>> On 10/28/25 8:04 AM, Yongxing Mou wrote: >>>> Previously, the eDP panel backlight was enabled via UEFI. Added backlight >>>> control node in kernel DTS due to some meta may not enable the backlight. >>>> >>>> Aligned with other x1e80100-based platforms: the PWM signal is controlled >>>> by PMK8550, and the backlight enable signal is handled by PMC8380. >>>> >>>> Signed-off-by: Yongxing Mou >>>> --- >>> >>> The subject must say "hamoa-iot-evk:" >> Thanks and got it , will fix it in next version.>> arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts | 55 ++++++++++++++++++++++++++++++ >>>>   1 file changed, 55 insertions(+) >>>> >>>> diff --git a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts >>>> index 36dd6599402b4650b7f8ad2c0cd22212116a25fe..fda1b3a3c7673be74832c27849231cba4bc1f25f 100644 >>>> --- a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts >>>> +++ b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts >>>> @@ -17,6 +17,16 @@ aliases { >>>>           serial1 = &uart14; >>>>       }; >>>>   +    backlight: backlight { >>>> +        compatible = "pwm-backlight"; >>>> +        pwms = <&pmk8550_pwm 0 5000000>; >>> >>> Try adjusting the backlight value.. you'll find some funny behavior >>> near the max level.. which reminds me I should send some fixes for >>> some laptop DTs >>> >>  I tried sliding the backlight between the maximum and minimum values. It seems that at a certain sliding speed, when approaching the maximum value, there is some brightness flickering. Is this the phenomenon you’re referring to?> [...] > > "maybe" - for me it was the brightness actually going down beyond ~80% > > The issue is that the PWM hardware can't really do a period that's > == 5000000 ns > > But it seems like this is no longer an issue since the driver now > rounds up to the closest supported value, see last couple commits > to drivers/leds/rgb/leds-qcom-lpg.c > > Konrad Oh,thanks for sharing that. I saw the phenomenon you mentioned. Previously, my baseline had already merged this patch series: https://lore.kernel.org/all/20250305-leds-qcom-lpg-fix-max-pwm-on-hi-res-v4-0-bfe124a53a9f@linaro.org/, so I didn’t observe the ‘brightness actually going down beyond ~80%.’and just very slight flickering. After I reverted patches, it indeed appeared. So here i want to confirm, pwms = <&pmk8550_pwm 0 5000000> can i keep the value 5000000 ?